A novel wideband H-shaped aperture-coupled H-slot microstrip antenna is proposed in this paper. As an example, this kind of microstrip antenna operating at Ku frequency band is designed and analyzed by using the finite-different time-domain (FDTD) method. A experimental prototype is also made. The measured results show that the prototype antenna could achieve 37.6% bandwidth for VSWR less than 2:1 and cross polarization less than -17dB.